How to use multiple C-MAP Genesis maps on your sonar/GPS unit

2-maps-on-same-unit-2-panel-collageAnglers and boaters can use multiple C-MAP Genesis maps on the same SD card or mini-SD card. This functionality is available for charts downloaded for free from Social Map and for custom Genesis Edge maps that users create with sonar recordings made with their own Lowrance depthfinders.

“We want to make C-MAP Genesis maps as easy to use as possible,” says Genesis Product Manager Matt Johnson. “We know keeping track of multiple SD cards can be difficult, as they are easily misplaced and lost. This advancement allows anglers, cruisers and sailors to keep their Insight Genesis custom maps conveniently stored on the same card, for easy use on the water.”  

microsd-cardPreviously, only one C-MAP Genesis map could be saved on an SD card for use on the water. Note, however, that multiple maps won’t all display at the same time on your GPS/sonar unit, but they will be easily accessible via the “Chart Options” window in your sonar units’ Chart page. This is a feature for HDS Gen2 , Gen3 and Carbon units only, at this time.

Follow these steps to save multiple maps to an SD card:

  1. Insert a blank 4 gB to 32 gB SD card into your computer
    • You do NOT need a special, expensive SD card
    • Any SD card of any brand will work
  2. Double click the SD-card icon on your computer to open the card’s directory file menu
  3. In your SD card’s directory create a folder for each waterbody on which you plan to launch your vessel
  4. Name the folders with the name of each waterbody
  5. If you’ve already created map files for each waterbody and have them saved onto your computer, a hard drive, or individual SD cards, follow these instructions:
    • Important: If you downloaded your map files and saved them on your computer prior to May 1, 2015, you should re-download them in order to ensure this new feature works correctly.
    • For each waterbody of interest, one at a time, copy all five of the map-creation files from the folder in which they are saved and then paste those five files into the corresponding waterbody folder on your SD
      • The five files will be named like this:
        • at5.xml
        • permits.txt
        • Vector_Large.at5
        • Vector_Medium.at5
        • Vector_Small.at5
    • Important: ALL 5 FILES are necessary for successful map display
  6. If you have not yet downloaded the map files you would like to save and use on one card, follow and repeat for each waterbody of interest the map-creation and download steps in these articles:
  7. After saving onto your SD card all of your folders containing map files, insert your SD card into your compatible* sonar/GPS unit.
  8. Soon after you insert your card, pop-up windows with Yes/No query will open for each of the waterbodies for which you created folders and saved onto your card
  9. Touch the “Yes” box for the map of the waterbody that you are on (or about to launch onto); touch “No” for all the other waterbodies saved onto the card
    • Because you have to click “No” for the maps you don’t want to load, it’s most convenient to load onto your cards only the folders for waterbodies that you likely will also be on during that day. (Examples: If you plan to lock up or down to another river pool, lake-hop around lakes/ponds a short driving distance from one another, or you’re on a waterbody that contiguously flows or opens into another separately named waterbody — a chain of lakes, for instanceIMG_1831
  10. To change from one map to another, the first step is to touch the “Chart Options” button in your chart screen (See image above)
  11. Next, touch the “Chart Source” button in the drop-down that opens (see image above). IMG_1833The menu of options will look like this (see image above). For this example, we’ve loaded free C-MAP Genesis Social Map charts for three semi-contiguous water bodies — they’re separated by dams — on the Wisconsin River. Below, are the line-items that appear in your menu of options in our example:
    • “Navionics” — If you touch this button, a Navionics map will load (if you have a Navionics card inserted in your unit’s second card slot
      • Even if you don’t have a Navionics card inserted, this option will appear. If you don’t have a card inserted and you touch this button, a very basic shape of the waterbody might load, or nothing at all will load and display on your screen
    • “Lowrance” — If you touch this button, your unit’s built-in base map will load (see image above, bottom panel)multiple-AT5-3-panel-collage
    • “Big Eau Plaine Reservoir” — Touch this button to load the map for this waterbody (top left, image above)
    • “Lake Du Bay” — Touch this button to load the map for this waterbody (top right, image above)
    • Wisconsion River Flowage” — Touch this button to load the map for this waterbody
  12. Now, simply touch the button/name for the map that you want to switch to
  13. To return to your chart menu and its full menu of options, touch the “Back” button

* To use C-MAP Genesis maps on the water, you’ll need a compatible Lowrance, Simrad or B&G chartplotter.

18 thoughts on “How to use multiple C-MAP Genesis maps on your sonar/GPS unit

  1. Great News! I have asked the question on this. I carry numerous maps as I am a mobile fisher. Won’t have to chase through multiple cards to get what I want.

  2. Hello
    Thanks for information.
    Is it also possible to use multiple
    Insight Genesis Maps on one card with a Simrad NSS ?
    I can only read one of twelve
    cards and it isn’t possible to change !?

    Greetings Michael

    1. Michael: I THINK so, but I’m not sure, because we don’t have a Simrad in my office to test it on. That said, the Simradd NSS runs on the same operatin system, essentially, as the Lowrance units, so I’m pretty sure it will work if you follow the same protocols as laid out in this article. — Regards, Greg Huff

  3. This feature works great!! The best thing would be if the Lowrance unit could just display all the maps on the card, like it works for the Lake Insight Pro cards. I’m sure there are technical reason why you haven’t been able to do that but it’s a goal to keep in mind.

  4. Is it only a feature on the touch models? I tried it on my HDS gen 2 7″ model (non-touch) and it won’t work. Have it updated and the maps are all recently downloaded. It won’t show! Any ideas?

    1. Kyle: I will test it out on an HDS 2 non-touch unit in the office and get back to you. It occurs to me now that we did not, at the time of publishing this article, test it out on non-touch units. — Greg

      1. Kyle: I was able to successfully load a card with two maps onto an HDS-5 Gen2 non-touch. Perhaps you can email me at and we can drill down deeper in order to troubleshoot your issue. — Regards, Huff

  5. Hey Greg,
    I managed to get both maps working finally. Maybe it was the SD cards? Either way this time around I tried 2 different sd cards and they both worked. Thank you for your help. One question though. These maps aren’t displaying the label for the lake when I renamed the folders. Just says Thunder Bay 243850, next map Thunder Bay 274467 etc. Any idea’s?
    Thanks Kyle

    1. Not at this time, Brent.

      If you have an HDS unit with two card slots, you could try loading a card with the Social Map chart into one slot and a card with your private trips on it — the data from both cards should display, however, where they overlap, it will likely be a little messy, as both sets of contours would show, but not necessarily match perfectly. If your privately mapped areas don’t overlap many areas on Social Map, this “hack” might work fairly well for you. I can confirm that I tried this hack and it worked, but that was a while back.

  6. I just tried this multiple lake trick with social maps on a new Lowrance Hook 5 unit. I am happy to report that it works (mostly)! I loaded a couple dozen lakes that I frequent, and they all loaded into the unit just fine. However, one lake in particular keeps glitching and won’t show the contour lines filled-in properly if I have more than one lake loaded onto my mSD card. Still troubleshooting…

  7. Hello everyone,
    Well, I just updated my Hook 5 with the new 2.0 software. However, this has REALLY messed up my social maps. I had previously been able to load multiple social maps at the same time per this pro tip by Greg. Unfortunately, now the unit errors out upon booting, and defaults to some random social map (with numeric names instead of common sense lake names) instead of to the built-in “Lowrance” map.

    I figured out that I can load the individual social maps (or the default Lowrance map) through the “Chart” submenu by selecting “Chart Data” and then the appropriate map. However, this has to be done each and EVERY time the power is cycled, which is FAR less than ideal!!!

    My request would be to PLEASE fix this issue for the next software update! Ideally, the unit would stay on the default “Lowrance” map upon boot-up, and then the user could later select the appropriate social map. I would also request that the social maps be loaded into the “chart data” menu by their filenames versus the 6 to 7 digit insight genesis map number. I’ll need to create a cheat sheet just for that, as I have about 25 different lakes loaded on my microSD card.

    Hope this gets some attention! Just sent essentially the same note to Lowrance technical support…


    1. J. Cross, thank you for bringing this to our attention. We have replicated some of the outcomes you described — except the crashing. It is most likely that 25 map files on one card is too much for the small processor in a Hook 5 to handle. Perhaps try a smaller amount of map files. Generally, we suggest keeping all your map file folders in a master folder on your computer and then only copying to your SD card the folders for only the waterbody(ies) you will actually be visiting on any given day.

      As for the display of the numbers, rather than the lake names — it appears that an unintended consequence of the software update was a bug in the code that affected how the lake names display. We have reported this to the software-update team and trust that the issue will be remedied in a future update. — Greg

  8. I am looking at the different options for Lowrance HDS Gen3. I have a and a 12. I bought a couple older versions (14 & 15) of Lowrance Insight Pro. There is a feature I looked for on the C-Map software I would like to have, and I’ve only seen it on C-Map ads. The feature is one that colors the contours of the lake at different depths different colors. I also have a question about the enhanced maps that Lowrance has advertised for their Carbon series units. Will they work on my non-Carbon units.

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